This invention relates generally to packaging of semiconductor wafers, and more particularly to a box closing apparatus for semiconductor wafer packaging.
The final stages of semiconductor wafer production are conventionally carried out in a clean room so that the finished wafers are free from particulate matter deposits and moisture. The condition of the wafers must be maintained as they are transported to a facility in another city or country. Moreover, the wafers must not be physically damaged either by the packaging process or by the rigors of their transportation.
Accordingly, specialized transportation boxes have been developed for transportation of the semiconductor wafers. Typically, these boxes contain a cassette which holds the wafers with minimal contact of the front and rear surfaces of the wafer. The wafers may be loaded into the cassette manually, or automatically by existing machinery. The loaded cassettes are manually placed in a lower portion of the box. An upper portion of the box is placed on the lower portion over the cassette and pressed down against the lower portion. The box is designed for a snap-latching interengagement of the upper and lower halves. To insure that the two halves are sealed together, tape is applied around the circumference of the box over the joint between the upper and lower halves. The box is then sealed inside a flexible, moisture barrier package (e.g., an aluminum coated acrylar polymer material).
The placement of the cassette into the wafer transport box and closing of the box are carried out by hand. To close the box after the loaded cassette is placed in the lower portion, a technician presses down on the upper portion of the box. It is often difficult to apply sufficiently even pressure of the upper portion of the box to interengage the upper and lower portions all of the way around the joint. As a result, the technician would have to take considerable time to achieve the joinder of the upper and lower portions. Occasionally, the box portions might not be fully interconnected all the way around the joint.